Fig. 1.

Summary of nanoparticle applications for treatment of brain tumors. Previous clinical work utilized systemic or intratumoral injections to deliver nanoparticles with direct cytotoxic activity on tumor cells either alone or in combination with radiation or magnetic hyperthermia. New preclinical avenues include intranasal nanoparticle delivery, the targeting of immune cells both inside the tumor and in the periphery, and photodynamic therapy to specifically mediate cell death at the tumor site. i.d. intradermal, s.c. subcutaneous, i.v. intravenous, r.t. radiotherapy, IO-NP iron-oxide nanoparticles